Subacute thyroiditis

This code represents an inflammatory condition of the thyroid gland that typically follows a viral infection. It is characterized by neck pain, tenderness over the thyroid, and transient hyperthyroidism followed by hypothyroidism, eventually resolving spontaneously.

Assign this code when documentation specifies subacute thyroiditis, also known as De Quervain's thyroiditis or granulomatous thyroiditis. Supporting documentation includes physician notes detailing the characteristic clinical presentation, laboratory findings (e.g., elevated ESR, transient thyroid hormone abnormalities), and imaging results consistent with the diagnosis.

• Differentiate from other forms of thyroiditis; specifically, do not code with autoimmune thyroiditis (E06.3) due to the Excludes1 note.
• Consider sequencing this code as the primary diagnosis if it is the reason for the encounter.
• Look for documentation of a preceding viral illness, though not always explicitly stated, as it is a common etiology.